Photobioreactors have been described for the use of cultivating alga and generally employ shallow lagoons agitated with one or more paddle wheels. Such bioreactors are plagued with problems including poor production of algae due to seasonal and daily climatic changes and contamination. Given that such bioreactors are generally constructed to receive the sun's daylight light, productivity is limited by intensity of the sun which depends on the photoperiod and the season, among other factors.